Williamsport, Pennsylvania, sits in USDA hardiness zone 6b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
The conditions favor cabbage, hazelnut, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Williamsport, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Williamsport lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Williamsport — soil, climate, flood, and parcel records. How we handle your address.
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Williamsport — the short answer
Williamsport, Pennsylvania: USDA zone 6b, about 206 days between hard freezes, across 6K acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 9
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~206
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 6K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 6b is Williamsport's average, not your lot's — a low corner or a tree line moves it. Against Williamsport's 206-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Williamsport
Each reading below is measured for Williamsport itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredWilliamsport runs about 206 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredWilliamsport sits in USDA hardiness zone 6b.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Williamsport is in
Williamsport sits in the Ridge and Valley — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Williamsport's own centroid, and it is not what its county reads: Lycoming County is mostly North Central Appalachians. The wider page above you is answering a different question about different ground.
What Grows in Williamsport
Every plant below cleared Williamsport's own zone 6b and its 206-day season. Each card opens that plant's Pennsylvania profile. How we score.
Is it too late to plant in Williamsport?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 12; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 9 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 1 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Williamsport
Spotted lanternfly documented 2 miles from Williamsport, first recorded 2019. What to watch for.
What's on the federal record near Williamsport
Closest first, within ~10 miles of Williamsport. Listing isn't leaking, and distance isn't exposure.
- PICKELNER AMOCO WESTUnderground Storage Tanks · 600 ft
- BIICHLE BODY SHOPBrownfields · 850 ft
- WILLIAMSPORT MOVING CO INCUnderground Storage Tanks · 1000 ft
- VEHICLE SVC FACUnderground Storage Tanks · 1100 ft
- WILLIAMSPORT AREA SCHOOL DISTBrownfields · 1100 ft
- WRAK RADIO STAUnderground Storage Tanks · 1100 ft
- PENNRAM DIVERSIFIED MFG CORPBrownfields · 1200 ft
- RIVER VALLEY TRANS SERVSBrownfields · 1300 ft
- GREYSTONE SVC STAUnderground Storage Tanks · 1300 ft
- WILLIAMSPORT OPRUnderground Storage Tanks · 1400 ft
- UGI PENN NATURAL GASBrownfields · 1500 ft
- PUBLIC SVC BLDGUnderground Storage Tanks · 1500 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Williamsport's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Williamsport.
Sources Checked
within ~10 miles of Williamsport
Severity Distribution
within ~10 miles of Williamsport
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Williamsport
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Williamsport average
Your land is one point inside Williamsport
Everything above resolves to Williamsport as a whole — one PHZM band and one 28°F frost record, read across 6K acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at city scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Williamsport Average
Williamsport Average
- ●USDA Zones 6b, averaged across Williamsport
- ●One soil character for all of Williamsport
- ●Frost dates read at Williamsport's scale: Apr 9 to Nov 1
YOUR Parcel
- ✓Your exact zone, not Williamsport's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Williamsport
Pull a site-specific report for your exact address in Williamsport, Pennsylvania — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Williamsport averages can't show:
We read public map data around Williamsport — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Williamsport average
How we know this about Williamsport
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Williamsport’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at city grain anywhere on this page — there is no city-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Williamsport
When does frost risk typically end in Williamsport?
The last hard freeze (28°F) in Williamsport typically lands around Apr 9, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Apr 30.
When is the first frost in Williamsport?
The first hard freeze (28°F) in Williamsport typically arrives around Nov 1, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 18, so the watching starts about Oct 2 — about 206 days after the spring freeze cleared.
How long is the growing season in Williamsport?
Measured between 28°F hard freezes, Williamsport sees about 206 frost-free days — roughly Apr 9 through Nov 1, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 30 to Oct 18, about 171 days.
Is the soil safe to grow vegetables in Williamsport?
The federal record around Williamsport is a meaningful one — 682 documented sites, mostly Underground Storage Tanks entries (372), the nearest Underground Storage Tanks record about 0.1 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Williamsport?
From about Oct 2 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 1 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 1. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Williamsport's scale — its 6b band and its 206-day season. Your yard writes its own version of Williamsport's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Williamsport’s own scale
7 of the readings below were taken at Williamsport's own scale — its own ~206-day season between 28°F freezes, the 5,617 acres it covers and 682 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Williamsport's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Williamsport's own 28°F hard-freeze dates, about Apr 9 and Nov 1 and the ~206-day span between themNOAA 1991–2020 Climate Normals
- 682 documented contamination sites on the federal record near Williamsport, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Williamsport's boundary and the 5,617 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~206-day seasonGrowable Ground crop-matching engine
- Williamsport sits in the Ridge and Valley — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Williamsportlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Williamsport's 5,617 acres read through its county's SSURGO summaryfrom Lycoming County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Lycoming County
- The growing challenges every Pennsylvania grower plans around — written at state scale, so they stay on the state guidefrom Pennsylvania
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Lycoming County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Williamsport's 5,617 acreswhy one lot differs from the next →
- Which side of Williamsport you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 5,617 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Williamsport-wide figureread your own land →
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